Eclipse cannot “retrieve ‘feature.xml'”, apparently.

I was getting the following error message in Eclipse, when I tried to use the software update (which, for some inexplicable reason, is accessible from the “help” menu):

Error retrieving “feature.xml”. [error in opening zip file]

Other than the fact that it probably shouldn’t have been appearing anyway, what’s particularly galling about this error message is that it offers no clue as to what the f*ck has gone wrong, nor even why it matters. The only visible effect of this error was that the eclipse update websites didn’t appear in the list, and that a dialog with the error message would pop up with just about any action I would take (other than closing the update dialog completely).

Very, very, stupid.

I did what I have increasingly found to be the quickest and easiest method of solving problems such as these: A Google search. It led me to this web page:

…Sure enough, deleting site.xml from inside my eclipse installation directory made the problem magically go away. It turns out that the eclipse CDT (C development tools) zip file which I had downloaded, was actually meant for retrieval via the eclipse updater and not meant to be installed by simply unzipping it inside my eclipse directory as I had done. Clearly the CDT guys are partly to blame for this because they don’t seem to actually provide any other downloadable version.

But… I mean, should the presence of some file in the installation directory really cause such an annoying problem? And if it does, shouldn’t the error message at least attempt to explain what the problem actually is?